Azo-lake color



Patented Nov. 7, 1922.

warren STATES DANIEL E. MGALLISTEB, OF PEDBICKTOWN', NEW JERSEY, ASSIGNOR TO E. I. DU FONT I PATENT OFFICE.

DE NEMOUBS & COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

AZO-LAKE COLOR.

N0 Drawing.

To all whom it may concern: I

Be it known that I, DANIEL E. MoALLIs'rER,

a citizen of the United States, and a resident Generally speaking, the lakes may be produced by precipitating the above-described azo dye on a substratum of aluminum hydroxide, the precipitating agent being preferably a barium salt. The ney process may be illustrated by the following examples I. Aluminum hydroxide is first prepared by adding a solution of lbs. of sodium carbonate in 125 gallons of Water to a solution of 100 lbs. of aluminum sulfate in 250 gallons of water at 212 F., and Washing the resulting AMOH) free from sulfates. 10 lbs. of the mono-azo dye dissolved in 120 gallons of water at 212 F. is then added to the purified aluminum hydroxide, and the dye is precipitated by adding to the mixture, maintained at a temperature of about 140 F, a solution of a0 lbs. of barium chloride in 40 gallons of water. The n'nxture is stirred for about one hour at a temperature of about 140 F., is then made up to a volume of about 5500 gallons by the addition of Water, and the water drawn oil; the pre Application filed February 11, 1922.

Serial No. 535,900.

cipitate is again made up to 5500 gallons, the Water drawn off, and the insoluble mass finally filtered and dried.

II. This example is the same as example I, except that the aluminum sulfate solution is treated with a solution containing 40, instead of 50, lbs. of sodium carbonate. The lake made according to this example is blue! in shade than the one made according to example I.

The new lakes are fairly fast to acids, alkalies, and water. The reactions of these lakes when brought into contact with yarious liquids may be indicated as follows With sulfuric acidbrown solution'with base insoluble.

/Vith Waterreddish brown, then bluish red solution.

lVith alcohol-insoluble.

With etherinsoluble.

With benzine-insoluble.

Upon reduction the new lakes in general become redder, the changes occurring upon reduction with various reducing agents being indicated as follows:-

Reducing agent. Color change.

Zinc and ammonium hydroxide. Colo'less, oxidizes in air to dull Stannous chloride and hydro- Light reddish blue, oxidizes to chloric acid. pale violet.

Zinc and hydrochloric acid. Colorless, oxidizes in air to yel w. Hydrosulphite. Colorless, oxidizes in air to pale yellow.

The properties of the lakes with respect to fastness may. be shown by the following table:

Fastness test (to bleeding).

Although my invention has been described in great detail in the above examples it will be understood that the proportions of materials used, and the temperatures and other conditions, may be varied to a certain extent without departing from the spirit and scope of the invention.

I claim 1. A lake comprising a mono-azo compound whose molecule includes the following atomic grouping:

associated with an aluminum compound.

2. A lake comprising a barium salt of a mono-azo dye whose molecule includes the following atomic grouping:

HQN\

associated with an aluminum compound.

3 A lake comprising a mono-azo compound whose molecule includes the followmg atomic grouping:

whose molecule includes the following atomic grouping said lake giving in sulfuric acid a brown solution and an insoluble residue, and yielding upon reduction with stannous chloride and hydrochloric acid a light reddish blue solution which, when oxidized, becomes pale violet.

5. The process of making a lake color which comprises precipitating from its water solution, by means 01": a solution of a barium salt, in the presence of aluminum hydroxide, a mono-azo compound whose molecule includes the following atomic grouping:

6. The process of making a lake color which comprises adding to 100' parts of aluminum sulfate in Water solution an alkaline-reacting sodium compound equivalent in amount to from about 40 to parts of sodium carbonate, washing free from sulfates the resulting precipitate of aluminum hydroxide, adding to the latter a solution containing 10 parts of the hereinbefore described mono-azo dye, precipitating a monoazo compound by adding a solution containing about 10 parts of barium chloride, stirring the resulting mixture while maintaining it at a temperature between 90 and 190 F. until the formation of the lake is completed, and then washing, filtering and drying the resulting lake.

In testimony whereof I aflix my signature.

DANIEL E. McALLISTER.

@ertificate of Correction It is hereby certified that in Letters Patent No. 1,43%,619, granted November 7,

1922, upon the application of Daniel E. ll/lcAllister, of Pedricktown, New Jersey,

for an improvement in Azo-Lake Colors, errors appear in the printed specification requiring correction as follows: Page 1, line 30, for the misspelled Word ney read new, and line 69, for the word henzine read 661120126; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of December, A. D, 1922.

[smell] KARL FENNING,

Acting Commissioner 0; Patents 

